Percentage Difference in Excel (change vs difference)

There are two different sums people mean. Pick the right one.

Percentage change (old → new)

=(B2-A2)/A2

Format as %. 400 → 500 = 25% up. 500 → 400 = −20% down. Same as =B2/A2-1.

Percentage difference (no before/after)

Comparing two shops, two quotes, two measurements — neither is the “starting” one:

=ABS(A2-B2)/AVERAGE(A2,B2)

400 and 500 → 22.2%. The answer is the same whichever order you put them.

Show + and − signs

Ctrl+1 › Custom: +0.0%;-0.0%;0.0%. Add colours: [Color10]+0.0%;[Red]-0.0%.

Old value is 0

You get #DIV/0!. Percentage change from zero isn’t defined, so show a note:

=IF(A2=0,"n/a",(B2-A2)/A2)

Negative starting values

Use ABS on the bottom so the direction stays right: =(B2-A2)/ABS(A2).

Percentage points vs percent

Margin 10% → 12% is 2 percentage points (=B2-A2), but a 20% change (=(B2-A2)/A2).

Other % sums: calculate a percentage · percentage formula